<template>
<div id="root">
  <div class="todo-container">
    <div class="todo-wrap">
		<MyHeader :addTodo='addTodo'/>
		<MyList :todos='todos' :checkTodo='checkTodo' :deleteTodo='deleteTodo'/>
		<MyFooter :todos='todos' :checkAllTodo='checkAllTodo' :clearAllTodo='clearAllTodo'/>
    </div>
  </div>
</div>
</template>

<script>

import MyHeader from './components/MyHeader.vue'
import MyList from './components/MyList.vue'
import MyFooter from'./components/MyFooter.vue'

	export default {
		name:'App',
		components:{MyHeader,MyList,MyFooter},		
    data(){
			return{
				todos:JSON.parse(localStorage.getItem('todos')) || []
      } // 第二次使用讀取上次使用的資料,若第一次使用,則設定為空數組
		},
    methods:{
      addTodo(todoObj){
				this.todos.unshift(todoObj)
			},
			//勾选or取消勾选一个todo
			checkTodo(id){
				this.todos.forEach((todo)=>{
					if(todo.id === id) todo.done = !todo.done
				})
			},
			//删除一个todo
			deleteTodo(id){
				this.todos = this.todos.filter( todo => todo.id !== id ) //數組過濾不會影響原數組,需要宣告一個值放置新數組
			},
      //全选or取消全选
			checkAllTodo(done){
				this.todos.forEach((todo)=>{
					todo.done = done
				})
			},
      clearAllTodo(){
        this.todos = this.todos.filter((todo)=>{
          return !todo.done
        }
        )
      }
    }, 
    watch:{ //深度監測,保持todos已勾選狀態
      todos:{
        deep:true,
        handler(value){
        localStorage.setItem('todos',JSON.stringify(value))
        }
      }
	}
  }
</script>


<style>
/*base*/
body {
  background: #fff;
}

.btn {
  display: inline-block;
  padding: 4px 12px;
  margin-bottom: 0;
  font-size: 14px;
  line-height: 20px;
  text-align: center;
  vertical-align: middle;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
  border-radius: 4px;
}

.btn-danger {
  color: #fff;
  background-color: #da4f49;
  border: 1px solid #bd362f;
}

.btn-danger:hover {
  color: #fff;
  background-color: #bd362f;
}

.btn:focus {
  outline: none;
}

.todo-container {
  width: 600px;
  margin: 0 auto;
}
.todo-container .todo-wrap {
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 5px;
}
</style>